Loud speaker



Jan- 5 1926- I 1,568,589

g. D. EDDINGTON LOUD SPEAKER Filed NOV. 25 1924 gram 1420a 6 .2. zddz y e Patented Jan. 5, 1926.

UNITED STATES PATENT oFFIcE."

a Gnome DOUGLAS EnnTNe'roN, or. SALT LAKE crry, UTAH, ASSIGNOR 'ro nnnmo'ron LOUD SPEAKER Inc, or SALT LAKE CITY, UTAH, A conronA'rrou or UTAH.

LOUD SPEAKER. v I

Application filed November 25, 1924. Serial No. 752,196.

To all whom it ma? concern:

' Be it known t at I, GEORGE DOUGLAS EDDINGTON, a citizen of the United States, residing at Salt Lake City, in the county of Salt Lake and State of Utah, have invented certain new and useful. Improvements 1n "Loud Speakers, of whichthe following is a specification.

.- f This invention relates to improvements in sound reproducing devices, operated electrically, and particularly to an electrically operated loud speaker adapted for use with radio receiving sets.

An object of the-invention is to provide a loud speaker, which will produce a greater volume of sound, by utilizing both current fluctuations for operating means to produce sound waves.

Another object of the invention resides in providing a loud speaker having a pair of sound reproducing diaphragms between v out departing from the spirit and scope of which is interposed electric means 0 erable through fluctuations in the current 1n sa d electric means for producing fluctuations in the sound producing means in a manner that the sound producin means will utilize all of the fluctuations 0% the current in the electrical means.

A further'object of the invention resides in providing a loud speaker including a pair of permanent magnets mounted at opposite ends of an electromagnet having an armature extending between the poles of said permanent magnet, and extending through the windings of the electromagnet, and operable byfluctuations' of current in said electromagnet, to produce an operating movement thereof, and connections between said armature and a pair of diaphragms for utilizing the oscillations in each direction for operating respective diaphragms to reproduce sound waves corresponding with said oscillations.

The invention also includes other objects and improvements in the details of construction and arrangement of parts which are more particularly-pointed out in the following detailed description and claims, directed to a preferred form of the invention, it

being understood, however, that various changesin the details of construction, and arrangement of parts may be made, withthe invention as described and claimed herem.

In the drawing, forming part ofi this application:

' igure 1 is a plan view, showm portions broken away, and in section, 0 the improved loud speaker. Figure 2 is a sectional view, taken on the line 2 -2 of Figure 1, the casing being omitted. 9 Figure 3 is a horizontal sectional view, taken on the line 3-3 of Figure 2.

Figure 4 is a vertical sectional view,

through the electromagnet, showingthe details of construction of the armature, and the mounting therefor.

1 indicates a cabinet which is shown in l linadjacent relation, and co-extensive conointly with the open front of said cabinet.

The casing section 3 has the inner ends of the openings4 threaded/for receiving the threaded extensions 7 of the diaphragm cup 8 having removable cover sections 9, to

permit the insertion or removal of the dia-j.

phragm 1% into their proper positions within the iaphragm cups 8..

The central portions of the covers -9 are provided with openings 11, and a rod 12 I extends axially through the openingsof both of the covers 9,.and is connected at its end ortions to the central portions of the diap ragms 10, in order that both 'of the diaphrafgms will vibrate synchronously.

. The opposed relation, and are spaced'ap'art in a manner as shown in Figure 1'. An elec tromagnet 13- is mounted with its axis aces'of the caps 9 are arrangedin parallel to the faces of the covers 9, and between said cover plates, theend portions abutting the poles of a pair of ring shaped permanent magnets 14 and 15 respectively.

U-shaped brackets 16 have the bridle por t-ions secured to the cap 9, while the leg portions aresecured to the magnets 14 and 15 by suitable screws 17, in order that the electromagnet and the permanent magnet may be permanently associated and mounted between the caps 9.-

The core 18 of the electromagnet .13 is formed of brass or other non-magnetic dotted lines, having an open front, closed so that the permanent magnets will normetal, and is formed with an elongatedplate is arranged normally at right angles of the diaphragms.

to the rod 12' connecting the diaphragms 10,

and is provided with a projection 22, from the central'portion of one end, adapted to be pivotally connected to said rod 12, in

order that the oscillation of the armature plate will effect an oscillation or vibration Each permanent magnet le and 15 respectively, is formed of a split ring memher, in which the opposite portions are cut indicated at 25.

form the poles to the magnet, in order that away atrespectively opposite sides, as-indicated at 23, to provide overlapped ends 24, which are spaced from each other, as These overlapped ends the magnetic flow from pole to pole will be in a direction parallel with the axis of the ring. These rings are mounted at opposite ends of the electromagnet 13 in a manner that the similar poles of each electromagnet l l and 15 respectively are arranged at opposite sides of the armature plate 20,

mally operate the armature plate in one a direction, to tension the diaphragm 10.

Suitable terminals 26 are mounted at one end of the bracket 16, under the screws 17,

and suitably insulated therefrom, and 'ref? .ceive the connections at-the-opposite ends of the coil 13," in order that the same may be interposed in the output circuit of a receiving set or other type of electrically operated sound amplifying means, in order that the'sounds in said output circuit may be reproduced; and further amplified.

afiect the fields of the magnets 14 and 15 respectively, and thereby effect the opera- 13 will set up a magnetic'field, which will v tion of the armature 20, and under the variations of this magnet field of the electro- 7 magnet 13, corresponding to the variations in the output circuit of the amplifying de vice, (not shown), for causing oscillation f of the armature plate 20, in accordance with a 7 these variations in the magnetic field, which will operate the diaphragms 10, for repro 'ducing the sounds, according to the fluctuations of the magnet field, so that both portions of the fluctuations onthe armature plate will be utilized in theproduction of sound waves directed outwardly through the amplifying horns 6,so thata maximum sound reproduction for the amount'of our; "reilit incircuit with the magnet 13 will re- -sut;' 1;

@ 1 In addition, the. use of {two permanent section, sound mounted in saiddiaphragm cups, a connectnaeaasa tion of the maximum strength of sound re production in the dialphragms 10, by the efficient operation of t e armature plate at bothv sides of the pivot or hinge 21, in order that a strong and yet clear sound reproduction may be had, utilizing the vibration or oscillation of the armature plate, in each direction.

What is claimed is: 1. A device of the class described comprising a pair of spaced parallel diaphragms, a rod connecting the central por- .tions of said diaphragms, an armature connected at one end to said rod and hingedly mounted at its central portion 'for oscillating movement, a pair of independent ring shaped permanent magnets arranged with the poles in opposed relation and operative relation with opposite ends of the armature plate, and an electromagnet arranged between said permanent magnets in close proximity to the poles thereof energizable for varying the magnetic efl'ect of both permanent magnets on the armature late, for o crating the armature plate an the diap ragm In accordance with the current variations of the electromagnet. Y 2; A device of the class described comprising a pair of spaced parallel diaphragms, means connecting said diaphragms for simultaneous operation, an armature hingedly mounted in its central portion for oscillating movement, and con-.

nected with the means connecting the diav.

phragm for oscillating said means in' an The energization of the electromagnet" manent vma g rnets arranged in operative relation with the opposite ends of the arma- I 'ture, each permanent magnet 0 crating the armature in a like manner, an an electromagnet positioned between the poles of the permanent magnet and adapted for connection with an output circuit of an electrically operated sound amplifying device, for" varying the fields of said permanent mag- 3 net, according to the fluctuations of current in circuit, and efi'ecting acorrespondingv operation or" the armatures and diaphragms in accordance with the fields fluc- I tuation.

- 3, A device of the class described comprising a casing formed with mating sections, a pair of diaphragm cups mounted in opposed relation in said casing havin sound outlets therethrough, horns mounter l in the sound outlet formed in the. casing reproducing. diaphragms magnet 'n1ounted between the diaphragms and having an elongated opening extending ing rod having the ends secured to the central portions of said diaphragms, an electroaXially through the central portion thereof,

an armature'plate hingedly mounted in its central portion in said elongated opening and 7 connected" with said connecting rod, for operating the diaphragms inthe oscillation of the armature plate, and a pair of permanent ring shaped magnets arranged at opposite sides of said electromagnet, for

effecting a similar operation on the arma ture, said electromagnet adapted to be conphragm utilizing the opposite portions of an oscillation in the reproduction. of a sound.

In testimony whereof I afiix my signature.

GEORGE DOUGLAS EDDINGTONI 

